Population Pharmacokinetics of Carbamazepine in Indian Epileptic Patients

Abstract

The aim of this study was to describe the population pharmacokinetics of carbamazepine in Indian epileptic patient population. The covariates evaluated were total body weight, height, age, dose, and gender. A total of 307 steady state serum concentrations were collected from 84 patients and analyzed. Population pharmacokinetic parameters were calculated using NONMEM, with one compartment first order absorption and elimination. The absorption rate was set at a fixed value of 1.2 h⁻¹. Exponential interindividual error and additive residual error model were developed. The model that was found to best describe the data following FO method was: Apparent Clearance (CL/F) (L/h)= 0.785 + 1.16 * (TBW/41.2) ** 0.75 * EXP (0.0976); Apparent Volume (V/F) (L) = 24.8 + 21.4 *(TBW/41.2)* EXP (0.740). Similarly the model found to best describe the data following FOCE method was CL/F (L/h) = 0.632 + 1.63 * (TBW/41.2) ** 0.75 * EXP (2.35E-12); V/F (L) = 31.8 + 56.9 *(TBW/41.2)* EXP (0.180).The final model estimates of CL/F and V/F estimated by FO method were 0.05 L/h/kg and 1.7 L/kg respectively and by FOCE method are 0.043 L/h/kg 1.43L/kg respectively. The typical body weight used for this population was 40 kg.

Key words: :

• Carbamazepine
• Indian Patients
• Population Pharmacokinetics